SSS-Class Soulmate

Introduction to the Work: "Why did you die instead of me!" "Because you're my only family." "But still, we're strangers." I died in place of my precious friend, who was like family. But I regressed?! Even if I die instead, the predetermined future is the extinction of humanity, and Gyeol is destined to die. The only way for both of us to survive is to prevent the extinction of humanity. I absolutely can't let Gyeol die! This time, I'm going to live happily! It's my first time regressing, but I'll become the best support and work hard to become stronger!